1. Field of the Invention
The present invention generally relates to wireless communications. More specifically, the present invention relates to dual band antenna arrays.
2. Description of the Related Art
In wireless communications systems, there is an ever-increasing demand for higher data throughput and reduced interference that can disrupt data communications. A wireless link in an Institute of Electrical and Electronic Engineers (IEEE) 802.11 network can be susceptible to interference from other access points and stations, other radio transmitting devices, and changes or disturbances in the wireless link environment between an access point and remote receiving node. The interference may degrade the wireless link thereby forcing communication at a lower data rate. The interference may, in some instances, be sufficiently strong as to disrupt the wireless link altogether.
FIG. 1 is a block diagram of a wireless device 100 in communication with one or more remote devices and as is generally known in the art. While not shown, the wireless device 100 of FIG. 1 includes antenna elements and a radio frequency (RF) transmitter and/or a receiver, which may operate using the 802.11 protocol. The wireless device 100 of FIG. 1 can be encompassed in a set-top box, a laptop computer, a television, a Personal Computer Memory Card International Association (PCMCIA) card, a remote control, a mobile telephone or smart phone, a handheld gaming device, a remote terminal, or other mobile device.
In one particular example, the wireless device 100 can be a handheld device that receives input through an input mechanism configured to be used by a user. The wireless device 100 may process the input and generate a corresponding RF signal. The generated RF signal may then be transmitted to one or more receiving nodes 110-140 via wireless links. Nodes 120-140 may receive data, transmit data, or transmit and receive data (i.e., a transceiver).
Wireless device 100 may also be an access point for communicating with one or more remote receiving nodes over a wireless link as might occur in an 802.11 wireless network. The wireless device 100 may receive data as a part of a data signal from a router connected to the Internet (not shown) or a wired network. The wireless device 100 may then convert and wirelessly transmit the data to one or more remote receiving nodes (e.g., receiving nodes 110-140). The wireless device 100 may also receive a wireless transmission of data from one or more of nodes 110-140, convert the received data, and allow for transmission of that converted data over the Internet via the aforementioned router or some other wired device. The wireless device 100 may also form a part of a wireless local area network (LAN) that allows for communications among two or more of nodes 110-140.
For example, node 110 can be a mobile device with WiFi capability. Node 110 (mobile device) may communicate with node 120, which can be a laptop computer including a WiFi card or wireless chipset. Communications by and between node 110 and node 120 can be routed through the wireless device 100, which creates the wireless LAN environment through the emission of RF and 802.11 compliant signals.
Receiving nodes 105-120 can be different types of devices which are configured to communicate at different frequencies. Receiving node 105 may operate at a first frequency or band and receiving node 110 may operate on a second frequency. Current wireless devices may include omnidirectional antennas that are vertically and horizontally polarized in a single band, but do not operate as omnidirectional in multiple bands. What is needed is a wireless device that includes omnidirectional and multi-polarization antennas which operates in dual band.